extend Authentication methods with an api

[bjrmatos]

let's say user wants to support authentication based on Bearer token with JWT secret key, issuer and audience checks, it should be possible for the user to extend the authentication methods supported with an API to avoid user repeating code like error handling, explicit login, basically things that can be handled by us under the hood with the API.

context: https://forum.jsreport.net/topic/3052/do-we-have-a-step-by-step-guide-on-how-to-setup-token-based-authentication-for-the-jsreport-api-for-consuming-the-reports